Windows下获取逻辑cpu数量和cpu核数量（用GetLogicalProcessorInformation，从XP3才开始有的API）

代码可在Windows NT下正常运行

具体API说明请参照如下文档：

GetLogicalProcessorInformation

点击打开链接

点击打开链接

点击打开链接

1. typedef BOOL (WINAPI *LPFN_GLPI)(PSYSTEM_LOGICAL_PROCESSOR_INFORMATION, PDWORD);
2. DWORD CountSetBits(ULONG_PTR bitMask)
3. {
4. DWORD LSHIFT = sizeof(ULONG_PTR)*8 - 1;
5. DWORD bitSetCount = 0;
6. ULONG_PTR bitTest = (ULONG_PTR)1 << LSHIFT;
7. DWORD i;
8. for (i = 0; i <= LSHIFT; ++i)
9. {
10. bitSetCount += ((bitMask & bitTest)?1:0);
11. bitTest/=2;
12. }
13. return bitSetCount;
14. }
15. LPFN_GLPI glpi;
16. glpi = (LPFN_GLPI) GetProcAddress(GetModuleHandle(TEXT("kernel32")),"GetLogicalProcessorInformation");
17. if (NULL == glpi)
18. {
19. printf("GetLogicalProcessorInformation is not supported.\n");
20. }
21. BOOL done = FALSE;
22. PSYSTEM_LOGICAL_PROCESSOR_INFORMATION buffer = NULL;
23. PSYSTEM_LOGICAL_PROCESSOR_INFORMATION ptr = NULL;
24. DWORD returnLength = 0;
25. while (!done)
26. {
27. DWORD rc = glpi(buffer, &returnLength);
28. if (FALSE == rc)
29. {
30. if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
31. {
32. if (buffer)
33. free(buffer);
34. buffer = (PSYSTEM_LOGICAL_PROCESSOR_INFORMATION)malloc(returnLength);
35. if (NULL == buffer)
36. {
37. printf("Error: Allocation failure\n");
38. return (2);
39. }
40. }
41. else
42. {
43. printf("Error %d\n", GetLastError());
44. return (3);
45. }
46. }
47. else
48. {
49. done = TRUE;
50. }
51. }
52. ptr = buffer;
53. DWORD byteOffset = 0;
54. DWORD logicalProcessorCount = 0;
55. DWORD processorCoreCount = 0;
56. while (byteOffset + sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION) <= returnLength)
57. {
58. switch (ptr->Relationship)
59. {
60. case RelationProcessorCore:
61. processorCoreCount++;
62. logicalProcessorCount += CountSetBits(ptr->ProcessorMask);
63. break;
64. }
65. byteOffset += sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION);
66. ptr++;
67. }
68. printf("logical:%d  core:%d\n", logicalProcessorCount, processorCoreCount);

http://blog.csdn.net/tobacco5648/article/details/22201169